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94d7c01a | 1 | /* Functions for memory limit warnings. |
acaf905b | 2 | Copyright (C) 1990, 1992, 2001-2012 Free Software Foundation, Inc. |
94d7c01a JA |
3 | |
4 | This file is part of GNU Emacs. | |
5 | ||
9ec0b715 | 6 | GNU Emacs is free software: you can redistribute it and/or modify |
94d7c01a | 7 | it under the terms of the GNU General Public License as published by |
9ec0b715 GM |
8 | the Free Software Foundation, either version 3 of the License, or |
9 | (at your option) any later version. | |
94d7c01a JA |
10 | |
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9ec0b715 | 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
94d7c01a | 18 | |
18160b98 | 19 | #include <config.h> |
d7306fe6 | 20 | #include <setjmp.h> |
b69a6d22 | 21 | #include <unistd.h> /* for 'environ', on AIX */ |
94d7c01a | 22 | #include "lisp.h" |
e231fd42 | 23 | #include "mem-limits.h" |
94d7c01a JA |
24 | |
25 | /* | |
26 | Level number of warnings already issued. | |
27 | 0 -- no warnings issued. | |
28 | 1 -- 75% warning already issued. | |
29 | 2 -- 85% warning already issued. | |
3b672b8f | 30 | 3 -- 95% warning issued; keep warning frequently. |
94d7c01a | 31 | */ |
395d3972 | 32 | enum warnlevel { not_warned, warned_75, warned_85, warned_95 }; |
395d3972 | 33 | static enum warnlevel warnlevel; |
94d7c01a | 34 | |
261cb4bb | 35 | typedef void *POINTER; |
8848b728 | 36 | |
94d7c01a JA |
37 | /* Function to call to issue a warning; |
38 | 0 means don't issue them. */ | |
a8fe7202 | 39 | static void (*warn_function) (const char *); |
94d7c01a | 40 | |
395d3972 RS |
41 | /* Start of data space; can be changed by calling malloc_init. */ |
42 | static POINTER data_space_start; | |
43 | ||
44 | /* Number of bytes of writable memory we can expect to be able to get. */ | |
45 | static unsigned long lim_data; | |
46 | \f | |
47 | ||
51757187 AS |
48 | #if defined (HAVE_GETRLIMIT) && defined (RLIMIT_AS) |
49 | static void | |
d3da34e0 | 50 | get_lim_data (void) |
51757187 AS |
51 | { |
52 | struct rlimit rlimit; | |
53 | ||
54 | getrlimit (RLIMIT_AS, &rlimit); | |
55 | if (rlimit.rlim_cur == RLIM_INFINITY) | |
56 | lim_data = -1; | |
57 | else | |
58 | lim_data = rlimit.rlim_cur; | |
59 | } | |
60 | ||
61 | #else /* not HAVE_GETRLIMIT */ | |
62 | ||
395d3972 RS |
63 | #ifdef USG |
64 | ||
65 | static void | |
7c3320d8 | 66 | get_lim_data (void) |
395d3972 RS |
67 | { |
68 | extern long ulimit (); | |
69 | ||
70 | lim_data = -1; | |
71 | ||
72 | /* Use the ulimit call, if we seem to have it. */ | |
73 | #if !defined (ULIMIT_BREAK_VALUE) || defined (GNU_LINUX) | |
74 | lim_data = ulimit (3, 0); | |
75 | #endif | |
76 | ||
77 | /* If that didn't work, just use the macro's value. */ | |
78 | #ifdef ULIMIT_BREAK_VALUE | |
79 | if (lim_data == -1) | |
80 | lim_data = ULIMIT_BREAK_VALUE; | |
81 | #endif | |
82 | ||
83 | lim_data -= (long) data_space_start; | |
84 | } | |
85 | ||
86 | #else /* not USG */ | |
87 | #ifdef WINDOWSNT | |
88 | ||
89 | static void | |
7c3320d8 | 90 | get_lim_data (void) |
395d3972 RS |
91 | { |
92 | extern unsigned long reserved_heap_size; | |
93 | lim_data = reserved_heap_size; | |
94 | } | |
95 | ||
96 | #else | |
0441987e | 97 | #if !defined (BSD4_2) && !defined (CYGWIN) |
395d3972 RS |
98 | |
99 | #ifdef MSDOS | |
100 | void | |
7c3320d8 | 101 | get_lim_data (void) |
395d3972 RS |
102 | { |
103 | _go32_dpmi_meminfo info; | |
8a445f76 | 104 | unsigned long lim1, lim2; |
395d3972 RS |
105 | |
106 | _go32_dpmi_get_free_memory_information (&info); | |
8a445f76 EZ |
107 | /* DPMI server of Windows NT and its descendants reports in |
108 | info.available_memory a much lower amount that is really | |
109 | available, which causes bogus "past 95% of memory limit" | |
110 | warnings. Try to overcome that via circumstantial evidence. */ | |
111 | lim1 = info.available_memory; | |
7cf94eac | 112 | lim2 = info.available_physical_pages; |
8a445f76 EZ |
113 | /* DPMI Spec: "Fields that are unavailable will hold -1." */ |
114 | if ((long)lim1 == -1L) | |
115 | lim1 = 0; | |
116 | if ((long)lim2 == -1L) | |
117 | lim2 = 0; | |
7cf94eac EZ |
118 | else |
119 | lim2 *= 4096; | |
8a445f76 EZ |
120 | /* Surely, the available memory is at least what we have physically |
121 | available, right? */ | |
7cf94eac | 122 | if (lim1 >= lim2) |
8a445f76 EZ |
123 | lim_data = lim1; |
124 | else | |
125 | lim_data = lim2; | |
126 | /* Don't believe they will give us more that 0.5 GB. */ | |
7cf94eac EZ |
127 | if (lim_data > 512U * 1024U * 1024U) |
128 | lim_data = 512U * 1024U * 1024U; | |
395d3972 | 129 | } |
ec06ec19 EZ |
130 | |
131 | unsigned long | |
7c3320d8 | 132 | ret_lim_data (void) |
ec06ec19 EZ |
133 | { |
134 | get_lim_data (); | |
135 | return lim_data; | |
136 | } | |
395d3972 RS |
137 | #else /* not MSDOS */ |
138 | static void | |
7c3320d8 | 139 | get_lim_data (void) |
395d3972 RS |
140 | { |
141 | lim_data = vlimit (LIM_DATA, -1); | |
142 | } | |
143 | #endif /* not MSDOS */ | |
144 | ||
0441987e | 145 | #else /* BSD4_2 || CYGWIN */ |
395d3972 RS |
146 | |
147 | static void | |
7c3320d8 | 148 | get_lim_data (void) |
395d3972 RS |
149 | { |
150 | struct rlimit XXrlimit; | |
151 | ||
152 | getrlimit (RLIMIT_DATA, &XXrlimit); | |
153 | #ifdef RLIM_INFINITY | |
154 | lim_data = XXrlimit.rlim_cur & RLIM_INFINITY; /* soft limit */ | |
155 | #else | |
156 | lim_data = XXrlimit.rlim_cur; /* soft limit */ | |
157 | #endif | |
158 | } | |
159 | #endif /* BSD4_2 */ | |
160 | #endif /* not WINDOWSNT */ | |
161 | #endif /* not USG */ | |
51757187 | 162 | #endif /* not HAVE_GETRLIMIT */ |
395d3972 RS |
163 | \f |
164 | /* Verify amount of memory available, complaining if we're near the end. */ | |
94d7c01a | 165 | |
fd065466 | 166 | static void |
d3da34e0 | 167 | check_memory_limits (void) |
94d7c01a | 168 | { |
968e9c04 | 169 | #ifdef REL_ALLOC |
d96be9fc | 170 | extern POINTER (*real_morecore) (long); |
968e9c04 | 171 | #endif |
d96be9fc | 172 | extern POINTER (*__morecore) (long); |
134994ae | 173 | |
94d7c01a | 174 | register POINTER cp; |
46b3623d RS |
175 | unsigned long five_percent; |
176 | unsigned long data_size; | |
395d3972 | 177 | enum warnlevel new_warnlevel; |
94d7c01a JA |
178 | |
179 | if (lim_data == 0) | |
180 | get_lim_data (); | |
3b672b8f | 181 | five_percent = lim_data / 20; |
94d7c01a JA |
182 | |
183 | /* Find current end of memory and issue warning if getting near max */ | |
968e9c04 AI |
184 | #ifdef REL_ALLOC |
185 | if (real_morecore) | |
186 | cp = (char *) (*real_morecore) (0); | |
187 | else | |
188 | #endif | |
fd065466 | 189 | cp = (char *) (*__morecore) (0); |
da396c5e | 190 | data_size = (char *) cp - (char *) data_space_start; |
94d7c01a | 191 | |
395d3972 RS |
192 | if (!warn_function) |
193 | return; | |
194 | ||
195 | /* What level of warning does current memory usage demand? */ | |
21da04c4 CY |
196 | new_warnlevel |
197 | = (data_size > five_percent * 19) ? warned_95 | |
198 | : (data_size > five_percent * 17) ? warned_85 | |
199 | : (data_size > five_percent * 15) ? warned_75 | |
200 | : not_warned; | |
395d3972 RS |
201 | |
202 | /* If we have gone up a level, give the appropriate warning. */ | |
203 | if (new_warnlevel > warnlevel || new_warnlevel == warned_95) | |
204 | { | |
205 | warnlevel = new_warnlevel; | |
206 | switch (warnlevel) | |
207 | { | |
208 | case warned_75: | |
209 | (*warn_function) ("Warning: past 75% of memory limit"); | |
210 | break; | |
211 | ||
212 | case warned_85: | |
213 | (*warn_function) ("Warning: past 85% of memory limit"); | |
214 | break; | |
215 | ||
216 | case warned_95: | |
217 | (*warn_function) ("Warning: past 95% of memory limit"); | |
218 | } | |
219 | } | |
220 | /* Handle going down in usage levels, with some hysteresis. */ | |
221 | else | |
222 | { | |
223 | /* If we go down below 70% full, issue another 75% warning | |
224 | when we go up again. */ | |
225 | if (data_size < five_percent * 14) | |
226 | warnlevel = not_warned; | |
227 | /* If we go down below 80% full, issue another 85% warning | |
228 | when we go up again. */ | |
229 | else if (warnlevel > warned_75 && data_size < five_percent * 16) | |
230 | warnlevel = warned_75; | |
231 | /* If we go down below 90% full, issue another 95% warning | |
232 | when we go up again. */ | |
233 | else if (warnlevel > warned_85 && data_size < five_percent * 18) | |
234 | warnlevel = warned_85; | |
235 | } | |
3b672b8f RS |
236 | |
237 | if (EXCEEDS_LISP_PTR (cp)) | |
da396c5e | 238 | (*warn_function) ("Warning: memory in use exceeds lisp pointer size"); |
94d7c01a | 239 | } |
395d3972 | 240 | \f |
5e617bc2 | 241 | #if !defined (CANNOT_DUMP) || !defined (SYSTEM_MALLOC) |
313d9eb2 DN |
242 | /* Some systems that cannot dump also cannot implement these. */ |
243 | ||
244 | /* | |
245 | * Return the address of the start of the data segment prior to | |
246 | * doing an unexec. After unexec the return value is undefined. | |
247 | * See crt0.c for further information and definition of data_start. | |
248 | * | |
249 | * Apparently, on BSD systems this is etext at startup. On | |
250 | * USG systems (swapping) this is highly mmu dependent and | |
251 | * is also dependent on whether or not the program is running | |
252 | * with shared text. Generally there is a (possibly large) | |
253 | * gap between end of text and start of data with shared text. | |
254 | * | |
255 | */ | |
256 | ||
8848b728 | 257 | char * |
313d9eb2 DN |
258 | start_of_data (void) |
259 | { | |
260 | #ifdef BSD_SYSTEM | |
261 | extern char etext; | |
262 | return (POINTER)(&etext); | |
263 | #elif defined DATA_START | |
264 | return ((POINTER) DATA_START); | |
265 | #elif defined ORDINARY_LINK | |
266 | /* | |
267 | * This is a hack. Since we're not linking crt0.c or pre_crt0.c, | |
268 | * data_start isn't defined. We take the address of environ, which | |
269 | * is known to live at or near the start of the system crt0.c, and | |
270 | * we don't sweat the handful of bytes that might lose. | |
271 | */ | |
313d9eb2 DN |
272 | return ((POINTER) &environ); |
273 | #else | |
274 | extern int data_start; | |
275 | return ((POINTER) &data_start); | |
276 | #endif | |
277 | } | |
278 | #endif /* (not CANNOT_DUMP or not SYSTEM_MALLOC) */ | |
279 | \f | |
395d3972 RS |
280 | /* Enable memory usage warnings. |
281 | START says where the end of pure storage is. | |
282 | WARNFUN specifies the function to call to issue a warning. */ | |
94d7c01a JA |
283 | |
284 | void | |
a8fe7202 | 285 | memory_warnings (POINTER start, void (*warnfun) (const char *)) |
94d7c01a | 286 | { |
d2aa42f8 | 287 | extern void (* __after_morecore_hook) (void); /* From gmalloc.c */ |
94d7c01a JA |
288 | |
289 | if (start) | |
290 | data_space_start = start; | |
3b672b8f RS |
291 | else |
292 | data_space_start = start_of_data (); | |
293 | ||
da396c5e | 294 | warn_function = warnfun; |
fd065466 | 295 | __after_morecore_hook = check_memory_limits; |
b78e8d0a | 296 | |
b78e8d0a AI |
297 | /* Force data limit to be recalculated on each run. */ |
298 | lim_data = 0; | |
94d7c01a | 299 | } |